<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, i nitial-scale=1.0" />
    <title>回调ref中回调执行次数问题</title>
  </head>
  <body>
    <!-- 准备好一个容器 -->
    <div id="test"></div>

    <!-- 引入react 核心库 -->
    <script
      type="text/javascript"
      src="../../react-js/react.development.js"
    ></script>
    <!-- 引入react-dom 用于支持react操作dom -->
    <script
      type="text/javascript"
      src="../../react-js/react-dom.development.js"
    ></script>
    <!-- 引入babel 用于jsx转为js -->
    <script type="text/javascript" src="../../react-js/babel.min.js"></script>

    <script type="text/babel">
      // 创建组件
      class RefDom extends React.Component {
        state = { isHot: true };

        showData = () => {
          const { input1 } = this;
          alert(input1.value);
        };
        changeWeather = () => {
          // 获取原来状态
          const { isHot } = this.state;
          // 更新状态
          this.setState({ isHot: !isHot });
        };

        saveInput = (c) => {
          this.input1 = c;
          console.log('@', c);
        };
        render() {
          const { isHot } = this.state;
          return (
            <div>
              <h2>今天天气很{isHot ? '炎热' : '凉爽'}</h2>
              {/*<input
                ref={(c) => {
                  this.input1 = c;
                  console.log('@', c);
                }}
                type='text'
                placeholder='点击按钮提示数据'
              />*/}
              <input
                ref={this.saveInput}
                type='text'
                placeholder='点击按钮提示数据'
              />
              <button onClick={this.showData}>点击我提示左侧输入框内容</button>
              <button onClick={this.changeWeather}>切换天气</button>
            </div>
          );
        }
      }
      // 渲染组件到页面
      ReactDOM.render(<RefDom />, document.getElementById('test'));
    </script>
  </body>
</html>
